A stressed skin structure is a structure whose main loads are supported by its exterior or “skin”, contrasting with non-load-bearing skin secured to rigid framework. Although this concept is mainly used in structures where maximum space and minimum weight are primary concerns, such as vehicles and aircraft, the principle can be applied to other stationary structures as well.
Stressed skin designs incorporated in architecture is minimal due to the cost. It’s considerably cheaper to construct a rigid framework such as a network of I-beams, and secure a non-load-bearing siding to it, than to say, pour a reinforced concrete wall, floor, and roof. Such designs are often structurally unnecessary and are therefore limited almost entirely to aesthetic and design-related uses.
An example of a stressed skin structure is the St. Louis Gateway Arch. (See image above)
Stressed Skin Design in Vehicles
As I mentioned above, a good example of a stressed skin structure is a car. A car must be relatively strong to impact as well as various types of loading, and it must also be spacious enough to accommodate passengers and cargo. It must also be as light as possible. The heavier a vehicle is the more fuel it consumes, making it less efficient both in terms of mileage and engine efficiency.
The heavier the vehicle is, not only will it use more fuel to propel itself forward, but it will require a comparatively larger engine, which by this fact alone demands more fuel. But at the same time, the housing structure, or vehicle body, must be strong enough to support the rigorous movements that a potential owner will subject it to.
Stressed skin designs are more often that not heavier, due to the superior materials used. Naturally, with our present technology, strength unfortunately also means weight.
But then again, it must be strong to impact and therefore cannot be constructed with a non-load-bearing exterior. It seems there really is only one viable option. – A stressed skin design.
All in all, taking the possibilities of physical collisions and spatial concerns into consideration, it makes reasonable sense that a stressed skin design is beneficial to that of a vehicle. Sacrificing a bit of weight for all the benefits is a worthy tradeoff, as it would not make sense to use a material that requires additional framing – even though lighter – if it cannot withstand external impact, not to mention design limitations.
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Discovery / Science Channel’s “How It’s Made” Aircraft Wings episode.
Video Rating: 4 / 5
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